| Message ID | 20240628060925.303309-2-horen.chuang@linux.dev (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | memory tier: consolidate the initialization of memory tiers | expand |
Hi, Jack, "Ho-Ren (Jack) Chuang" <horen.chuang@linux.dev> writes: I suggest you to merge the [0/1] with the change log here. [0/1] describes why do we need the patch. The below text describes some details. Just don't use "---" to separate them. We need both parts in the final commit message. > If we simply move the set_node_memory_tier() from memory_tier_init() > to late_initcall(), it will result in HMAT not registering > the mt_adistance_algorithm callback function, because > set_node_memory_tier() is not performed during the memory tiering > initialization phase, leading to a lack of correct default_dram > information. > > Therefore, we introduced a nodemask to pass the information of the > default DRAM nodes. The reason for not choosing to reuse > default_dram_type->nodes is that it is not clean enough. So in the end, > we use a __initdata variable, which is a variable that is released once > initialization is complete, including both CPU and memory nodes for HMAT > to iterate through. > > Besides, since default_dram_type may be checked/used during the > initialization process of HMAT and drivers, it is better to keep the > allocation of default_dram_type in memory_tier_init(). Why do we need it? IIRC, we have deleted its usage in hmat.c. > Signed-off-by: Ho-Ren (Jack) Chuang <horenchuang@bytedance.com> > Suggested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > --- > drivers/acpi/numa/hmat.c | 5 +-- > include/linux/memory-tiers.h | 2 ++ > mm/memory-tiers.c | 59 +++++++++++++++--------------------- > 3 files changed, 28 insertions(+), 38 deletions(-) > > diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c > index 2c8ccc91ebe6..a2f9e7a4b479 100644 > --- a/drivers/acpi/numa/hmat.c > +++ b/drivers/acpi/numa/hmat.c > @@ -940,10 +940,7 @@ static int hmat_set_default_dram_perf(void) > struct memory_target *target; > struct access_coordinate *attrs; > > - if (!default_dram_type) > - return -EIO; > - > - for_each_node_mask(nid, default_dram_type->nodes) { > + for_each_node_mask(nid, default_dram_nodes) { > pxm = node_to_pxm(nid); > target = find_mem_target(pxm); > if (!target) > diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h > index 0d70788558f4..fa61ad9c4d75 100644 > --- a/include/linux/memory-tiers.h > +++ b/include/linux/memory-tiers.h > @@ -38,6 +38,7 @@ struct access_coordinate; > #ifdef CONFIG_NUMA > extern bool numa_demotion_enabled; > extern struct memory_dev_type *default_dram_type; Can we remove the above line? > +extern nodemask_t default_dram_nodes __initdata; We don't need to use __initdata in variable declaration. > struct memory_dev_type *alloc_memory_type(int adistance); > void put_memory_type(struct memory_dev_type *memtype); > void init_node_memory_type(int node, struct memory_dev_type *default_type); > @@ -76,6 +77,7 @@ static inline bool node_is_toptier(int node) > > #define numa_demotion_enabled false > #define default_dram_type NULL > +#define default_dram_nodes NODE_MASK_NONE Should we use <tab> after "default_dram_nodes"? > /* > * CONFIG_NUMA implementation returns non NULL error. > */ > diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c > index 6632102bd5c9..a19a90c3ad36 100644 > --- a/mm/memory-tiers.c > +++ b/mm/memory-tiers.c > @@ -43,6 +43,7 @@ static LIST_HEAD(memory_tiers); > static LIST_HEAD(default_memory_types); > static struct node_memory_type_map node_memory_types[MAX_NUMNODES]; > struct memory_dev_type *default_dram_type; > +nodemask_t default_dram_nodes __initdata = NODE_MASK_NONE; > > static const struct bus_type memory_tier_subsys = { > .name = "memory_tiering", > @@ -671,28 +672,38 @@ EXPORT_SYMBOL_GPL(mt_put_memory_types); > > /* > * This is invoked via `late_initcall()` to initialize memory tiers for > - * CPU-less memory nodes after driver initialization, which is > - * expected to provide `adistance` algorithms. > + * memory nodes, both with and without CPUs. After the initialization of > + * firmware and devices, adistance algorithms are expected to be provided. > */ > static int __init memory_tier_late_init(void) > { > int nid; > + struct memory_tier *memtier; > > + get_online_mems(); > guard(mutex)(&memory_tier_lock); > + /* > + * Look at all the existing and uninitialized N_MEMORY nodes and > + * add them to default memory tier or to a tier if we already have > + * memory types assigned. > + */ If the memory type of the node has been assigned, we will skip it in the following code. So, I think that we need to revise the comments. > for_each_node_state(nid, N_MEMORY) { > /* > - * Some device drivers may have initialized memory tiers > - * between `memory_tier_init()` and `memory_tier_late_init()`, > - * potentially bringing online memory nodes and > - * configuring memory tiers. Exclude them here. > + * Some device drivers may have initialized > + * memory tiers, potentially bringing memory nodes > + * online and configuring memory tiers. > + * Exclude them here. > */ > if (node_memory_types[nid].memtype) > continue; > > - set_node_memory_tier(nid); > + memtier = set_node_memory_tier(nid); > + if (IS_ERR(memtier)) > + /* Continue with memtiers we are able to setup. */ > + break; > } > - > establish_demotion_targets(); > + put_online_mems(); > > return 0; > } > @@ -875,8 +886,7 @@ static int __meminit memtier_hotplug_callback(struct notifier_block *self, > > static int __init memory_tier_init(void) > { > - int ret, node; > - struct memory_tier *memtier; > + int ret; > > ret = subsys_virtual_register(&memory_tier_subsys, NULL); > if (ret) > @@ -887,7 +897,8 @@ static int __init memory_tier_init(void) > GFP_KERNEL); > WARN_ON(!node_demotion); > #endif > - mutex_lock(&memory_tier_lock); > + > + guard(mutex)(&memory_tier_lock); > /* > * For now we can have 4 faster memory tiers with smaller adistance > * than default DRAM tier. > @@ -897,29 +908,9 @@ static int __init memory_tier_init(void) > if (IS_ERR(default_dram_type)) > panic("%s() failed to allocate default DRAM tier\n", __func__); > > - /* > - * Look at all the existing N_MEMORY nodes and add them to > - * default memory tier or to a tier if we already have memory > - * types assigned. > - */ > - for_each_node_state(node, N_MEMORY) { > - if (!node_state(node, N_CPU)) > - /* > - * Defer memory tier initialization on > - * CPUless numa nodes. These will be initialized > - * after firmware and devices are initialized. > - */ > - continue; > - > - memtier = set_node_memory_tier(node); > - if (IS_ERR(memtier)) > - /* > - * Continue with memtiers we are able to setup > - */ > - break; > - } > - establish_demotion_targets(); > - mutex_unlock(&memory_tier_lock); > + /* Record nodes with memory and CPU to set default DRAM performance. */ > + nodes_and(default_dram_nodes, node_states[N_MEMORY], > + node_states[N_CPU]); > > hotplug_memory_notifier(memtier_hotplug_callback, MEMTIER_HOTPLUG_PRI); > return 0; -- Best Regards, Huang, Ying
diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c index 2c8ccc91ebe6..a2f9e7a4b479 100644 --- a/drivers/acpi/numa/hmat.c +++ b/drivers/acpi/numa/hmat.c @@ -940,10 +940,7 @@ static int hmat_set_default_dram_perf(void) struct memory_target *target; struct access_coordinate *attrs; - if (!default_dram_type) - return -EIO; - - for_each_node_mask(nid, default_dram_type->nodes) { + for_each_node_mask(nid, default_dram_nodes) { pxm = node_to_pxm(nid); target = find_mem_target(pxm); if (!target) diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h index 0d70788558f4..fa61ad9c4d75 100644 --- a/include/linux/memory-tiers.h +++ b/include/linux/memory-tiers.h @@ -38,6 +38,7 @@ struct access_coordinate; #ifdef CONFIG_NUMA extern bool numa_demotion_enabled; extern struct memory_dev_type *default_dram_type; +extern nodemask_t default_dram_nodes __initdata; struct memory_dev_type *alloc_memory_type(int adistance); void put_memory_type(struct memory_dev_type *memtype); void init_node_memory_type(int node, struct memory_dev_type *default_type); @@ -76,6 +77,7 @@ static inline bool node_is_toptier(int node) #define numa_demotion_enabled false #define default_dram_type NULL +#define default_dram_nodes NODE_MASK_NONE /* * CONFIG_NUMA implementation returns non NULL error. */ diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c index 6632102bd5c9..a19a90c3ad36 100644 --- a/mm/memory-tiers.c +++ b/mm/memory-tiers.c @@ -43,6 +43,7 @@ static LIST_HEAD(memory_tiers); static LIST_HEAD(default_memory_types); static struct node_memory_type_map node_memory_types[MAX_NUMNODES]; struct memory_dev_type *default_dram_type; +nodemask_t default_dram_nodes __initdata = NODE_MASK_NONE; static const struct bus_type memory_tier_subsys = { .name = "memory_tiering", @@ -671,28 +672,38 @@ EXPORT_SYMBOL_GPL(mt_put_memory_types); /* * This is invoked via `late_initcall()` to initialize memory tiers for - * CPU-less memory nodes after driver initialization, which is - * expected to provide `adistance` algorithms. + * memory nodes, both with and without CPUs. After the initialization of + * firmware and devices, adistance algorithms are expected to be provided. */ static int __init memory_tier_late_init(void) { int nid; + struct memory_tier *memtier; + get_online_mems(); guard(mutex)(&memory_tier_lock); + /* + * Look at all the existing and uninitialized N_MEMORY nodes and + * add them to default memory tier or to a tier if we already have + * memory types assigned. + */ for_each_node_state(nid, N_MEMORY) { /* - * Some device drivers may have initialized memory tiers - * between `memory_tier_init()` and `memory_tier_late_init()`, - * potentially bringing online memory nodes and - * configuring memory tiers. Exclude them here. + * Some device drivers may have initialized + * memory tiers, potentially bringing memory nodes + * online and configuring memory tiers. + * Exclude them here. */ if (node_memory_types[nid].memtype) continue; - set_node_memory_tier(nid); + memtier = set_node_memory_tier(nid); + if (IS_ERR(memtier)) + /* Continue with memtiers we are able to setup. */ + break; } - establish_demotion_targets(); + put_online_mems(); return 0; } @@ -875,8 +886,7 @@ static int __meminit memtier_hotplug_callback(struct notifier_block *self, static int __init memory_tier_init(void) { - int ret, node; - struct memory_tier *memtier; + int ret; ret = subsys_virtual_register(&memory_tier_subsys, NULL); if (ret) @@ -887,7 +897,8 @@ static int __init memory_tier_init(void) GFP_KERNEL); WARN_ON(!node_demotion); #endif - mutex_lock(&memory_tier_lock); + + guard(mutex)(&memory_tier_lock); /* * For now we can have 4 faster memory tiers with smaller adistance * than default DRAM tier. @@ -897,29 +908,9 @@ static int __init memory_tier_init(void) if (IS_ERR(default_dram_type)) panic("%s() failed to allocate default DRAM tier\n", __func__); - /* - * Look at all the existing N_MEMORY nodes and add them to - * default memory tier or to a tier if we already have memory - * types assigned. - */ - for_each_node_state(node, N_MEMORY) { - if (!node_state(node, N_CPU)) - /* - * Defer memory tier initialization on - * CPUless numa nodes. These will be initialized - * after firmware and devices are initialized. - */ - continue; - - memtier = set_node_memory_tier(node); - if (IS_ERR(memtier)) - /* - * Continue with memtiers we are able to setup - */ - break; - } - establish_demotion_targets(); - mutex_unlock(&memory_tier_lock); + /* Record nodes with memory and CPU to set default DRAM performance. */ + nodes_and(default_dram_nodes, node_states[N_MEMORY], + node_states[N_CPU]); hotplug_memory_notifier(memtier_hotplug_callback, MEMTIER_HOTPLUG_PRI); return 0;
If we simply move the set_node_memory_tier() from memory_tier_init() to late_initcall(), it will result in HMAT not registering the mt_adistance_algorithm callback function, because set_node_memory_tier() is not performed during the memory tiering initialization phase, leading to a lack of correct default_dram information. Therefore, we introduced a nodemask to pass the information of the default DRAM nodes. The reason for not choosing to reuse default_dram_type->nodes is that it is not clean enough. So in the end, we use a __initdata variable, which is a variable that is released once initialization is complete, including both CPU and memory nodes for HMAT to iterate through. Besides, since default_dram_type may be checked/used during the initialization process of HMAT and drivers, it is better to keep the allocation of default_dram_type in memory_tier_init(). Signed-off-by: Ho-Ren (Jack) Chuang <horenchuang@bytedance.com> Suggested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> --- drivers/acpi/numa/hmat.c | 5 +-- include/linux/memory-tiers.h | 2 ++ mm/memory-tiers.c | 59 +++++++++++++++--------------------- 3 files changed, 28 insertions(+), 38 deletions(-)